Filter media and filter element with adhesive reinforcing

ABSTRACT

A method of reinforcing a filter media pack as well as a reinforced media pack is provided. The method includes forming a media pack to have an inlet face and an outlet face. The method includes applying a reinforcing agent to the media pack. The reinforcing agent is applied in a flowable state. The method also includes hardening the reinforcing agent to form a reinforcing structure to reinforce the media pack. Filter element having such a reinforcing structure is also provided.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application is a continuation of co-pendingPCT/US2015/054739, filed Oct. 8, 2015, designating the United States,which claims the benefit of U.S. Provisional Patent Application No.62/062,516, filed Oct. 10, 2014, the entire teachings and disclosure ofwhich are incorporated herein by reference thereto.

FIELD OF THE INVENTION

This invention generally relates to filter media and filter elements andparticularly to filter elements that include reinforcing structures forreinforcing the filter media of the filter element.

BACKGROUND OF THE INVENTION

Filters are used to remove impurities from a flow of fluid such as aliquid or a gas. The filter will typically include porous filter mediathat traps the impurities as the fluid flows through the filter media.

One particular type of media is a fluted type media that is formed froma plurality of adjacent layers of filter media. The layers define aplurality of flutes that form either inlet or outlet flutes depending onwhich flutes are open at an inlet side and closed at the outlet side orclosed at the inlet side and open on the outlet side of the filter.Typically, the layers of media are formed from a facer sheet secured toa corrugated or fluted sheet. This composite structure can then be woundto form a plurality of adjacent layers from a single continuous strip orcan be cut into segments and then stacked to form a plurality ofadjacent layers.

A seal arrangement is also typically attached to the filter media toreleasably seal the filter media within a housing. This seal can be aradially directed seal or an axially directed seal. Typically, the sealis a relatively soft and compliant material so that it forms a goodfluid tight seal with a corresponding surface of the housing. The sealarrangement is typically attached to an outer peripheral surface of themedia.

A pressure differential will exist across the filter media to force thefluid to flow through the media. In many systems, the pressuredifferential is generated by a vacuum on a downstream side of the filtermedia. A vacuum across the media presents several problems, particularlywith regard to the layered fluted type media.

This vacuum can cause radially inwardly directed compression of thefilter media reducing the size of the outer periphery of the media. Thisreduction in size can cause several problems. This can cause thecompliant seal to be drawn radially inward as well. If the seal is aradially directed seal, this can cause the seal to disengage from thehousing sealing surface and create a leak path or, at a minimum, reducethe quality of the seal between the seal arrangement and housing.

Further, if the seal is an axial seal, the seal arrangement is oftenaxially pinched between portions of the housing. When the filter mediareduces in size while the seal is held firm between portions of thehousing, this can cause the connection between the seal arrangement andmedia to become destroyed. Alternatively, it can cause the layers of thefilter media to separate. Either of these problems can createundesirable leak paths.

A further problem particularly related to fluted media is that thepressure differential across the filter media can cause the adjacentlayers to slip relative to one another, which is often referred astelescoping. This telescoping of the media can also create leak paths.Further, when the layers telescope, the problems relating to vacuumdiscussed above can be exacerbated.

Another type of media is pleated media that is typically a singlecontinuous piece of filter media that is folded to form a plurality ofadjacent panels interconnected by the folds. The interconnected panelsform a plurality of peaks and valleys. One problem with this form ofmedia is that the peaks on an inlet side of the filter may be directlyexposed to impingement of impurities as well as another action that cancause cracking or damage to the filter media at the peaks.

Embodiments of the present invention are aimed at rectifying one or moreof these problems or otherwise providing improvements over the art.

BRIEF SUMMARY OF THE INVENTION

In one embodiment of the invention, a new and improved method ofreinforcing a media pack is provided. The method includes forming amedia pack to have an inlet face and an outlet face. The method includesapplying a reinforcing agent to the media pack. The reinforcing agent isapplied in a flowable state. The method also includes hardening thereinforcing agent to form a reinforcing structure to reinforce the mediapack.

In some methods, the reinforcing agent is applied proximate at least oneof the inlet face and the outlet face.

In one method, applying the reinforcing agent includes immersing atleast one of the inlet face and the outlet face in the reinforcingagent. This may be done using a bath housing the reinforcing agent inthe flowable state.

In one method, applying the reinforcing agent includes immersing lessthan the entire media pack in the reinforcing agent.

In more particular embodiments, the reinforcing agent may be, in theflowable state, a liquid or a powder.

In one method, hardening the reinforcing agent includes exposing thereinforcing agent to predetermined wavelength of a light.

In one method, hardening the reinforcing agent includes heating thereinforcing agent.

In one method, hardening the reinforcing agent includes drying thereinforcing agent without heating the reinforcing agent.

In one method, the media pack is z-media having a plurality of adjacentlayers of fluted filter media defining the inlet face and the outletface. Each layer includes a corrugated sheet and a facer sheet attachedto the corrugated sheet to form a plurality of inlet and outlet flutesextending between the inlet and outlet faces.

In one method, the inlet flutes have an open end proximate the inlet endand a closed end proximate the outlet end. The outlet flutes have aclosed end proximate the inlet end and an open end proximate the outletend, the reinforcing agent does not close the open ends of the flutes.

In one method, the inlet flutes are open proximate the inlet end andclosed proximate the outlet end by outlet end sealant and the outletflutes are closed proximate the inlet end by inlet end sealant and openproximate the outlet end. The reinforcing agent being different than theinlet end sealant and outlet end sealant.

In one method, the inlet and outlet end sealant has a higher viscositythan the reinforcing agent when in a flowable state.

In one method, the method further includes attaching a seal member tothe media pack adjacent the reinforcing agent. The seal member mayprovide a radially outward directed seal surface. The seal member mayprovide an axially directed seal surface.

In one method, the seal member is molded directly to an outer peripheryof the media pack.

In one method, a portion of the seal member overlaps with a portion ofthe reinforcing agent.

In one method, the reinforcing agent is applied to only a portion of thecross-section of the media pack. In one method, the reinforcing agent isapplied proximate an outer periphery of the corresponding face of thefilter media pack.

In one method, applying the reinforcing agent includes absorbing thereinforcing agent into media of the media pack. In one method, applyingthe reinforcing agent includes coating surfaces of filter media of themedia pack with the reinforcing agent.

In one method, the method further includes coupling a plurality oflayers of media together to form the media pack.

In one method, applying the reinforcing agent occurs while coupling theadjacent layers of media.

In one method, applying the reinforcing agent occurs after coupling theadjacent layers of media.

In one method, coupling a plurality of layers of media together occursby winding a single strip of media to form a coiled media pack.

In one method, coupling a plurality of layers of media together occursby stacking a plurality of strips or segments of media to form a stackedmedia pack.

In one method, the media is provided by z-media. Each layer includes acorrugated sheet and a facer sheet attached to the corrugated sheet toform a plurality of inlet and outlet flutes extending between the inletand outlet faces.

In one method, applying the reinforcing agent includes spraying thereinforcing agent onto the filter media pack or the media pack prior toforming the pack. Applying the reinforcing agent may include wiping thereinforcing agent onto the filter media pack or the media prior toforming the pack.

In one method, the reinforcing agent extends at least 0.100 inch, andpreferably 0.125 inch into the filter media pack from one of the flowfaces.

In one method, hardening the reinforcing agent includes applying asecond material to the reinforcing agent to cure the reinforcing agent.In a more particular embodiment, the reinforcing agent and secondmaterial are a multipart epoxy.

In one method, the reinforcing agent is impregnated into the media ofthe filter media pack such that the filter media forms a substrate. Thereinforcing agent extends through the media prior to the step ofhardening such that the reinforcing structure is comprised of a matrixof the hardened reinforcing agent and the media substrate.

In a further embodiment, a filter media pack is provided having filtermedia and a reinforcing structure. The filter media has an inlet faceand an outlet face. The reinforcing structure is a composite structurecomprising a reinforcing agent impregnated into the filter media suchthat the filter media forms a substrate and the reinforcing agent formsa hardened matrix.

The filter media forms a plurality of pores therethrough and thereinforcing agent extends through at least some of the pores entirelythrough the filter media.

In one embodiment, the reinforcing structure is formed proximate one ofthe inlet face and outlet face. In one embodiment, a reinforcementstructure is formed proximate both the inlet and outlet faces.

In one embodiment, a seal arrangement is attached to the filter mediaproximate the reinforcing structure.

The filter media may be fluted media (also referred to as z-media). Thefilter media may be pleated media.

In one embodiment, the seal arrangement includes a seal member thatprovides a radially outward directed seal surface. Alternatively, theseal member could provide an axially directed seal surface.

In one embodiment, the filter media is z-media having a plurality ofadjacent layers of fluted filter media defining the inlet face and theoutlet face. Each layer includes a corrugated sheet and a facer sheetattached to the corrugated sheet. The layers of fluted filter media forma plurality of inlet and outlet flutes extending between the inlet andoutlet faces.

In one embodiment, the inlet flutes are open proximate the inlet end andclosed proximate the outlet end by outlet end sealant. The outlet flutesare closed proximate the inlet end by inlet end sealant and openproximate the outlet end. The reinforcing agent is different than theinlet end sealant and outlet end sealant in at least one physicalcharacteristic. In one embodiment, the characteristic is viscosity in aflowable state.

In one embodiment, the inlet flutes have an open end proximate the inletend and a closed end proximate the outlet end. The outlet flutes have aclosed end proximate the inlet end and an open end proximate the outletend. The reinforcing agent does not close the open ends of the flutes.In a more particular embodiment, the reinforcing agent takes up lessthan 20% the cross-sectional area of the open ends of the flutes. In amore particular embodiment, the reinforcing agent takes up less than 10%the cross sectional area of the open ends of the flutes.

In one embodiment, a filter media pack is provided. The filter mediapack is formed by the process comprising the steps of: providing afilter media pack having an inlet face and an outlet face; absorbing areinforcing agent in a liquid state into media pack; and hardening thereinforcing agent to a solid to provide structural rigidity to thefilter media pack. The reinforcing agent may be, in a more particularembodiment, located proximate one of the inlet or outlet faces.

In one embodiment, a filter media pack is provided including a pluralityof layers of fluted filter media and a reinforcing component. Theplurality of adjacent layers of fluted filter media defines an inletface and an outlet face. Each layer including a corrugated sheet and afacer sheet attached to the corrugated sheet to form a plurality ofinlet and outlet flutes extending between the inlet and outlet faces.The reinforcing component is applied to the filter media in a flowablestate and then hardened to a solid state to reinforce the filter media.In one more particular embodiment reinforcing component is locatedadjacent the inlet and/or outlet face.

In one embodiment, a filter media pack is provided. The filter mediapack includes a plurality of layers of fluted filter media. Each layerof fluted filter media includes a fluted sheet forming a plurality ofpeaks and valleys attached to a first face of a facer sheet forming aplurality of flutes between the facer sheet and the fluted sheet. Theflutes extending between a first edge and a second edge. The facer sheetforming a second face opposite the first face. At least one first stitchbead secures adjacent layers together. The first stitch bead is formedbetween the fluted sheet of a first layer of filter media and the secondface of the facer sheet of an adjacent second layer of filter media. Thefirst stitch bead does not close the flutes formed between the first andsecond layer of filter media.

In a particular embodiment, the first stitch bead extends less than anentire distance between adjacent peaks of the fluted sheet.

In a particular embodiment, each layer of fluted filter media includes afirst seal bead between the fluted sheet and the facer sheet closing offflutes formed between the facer sheet and the fluted sheet. A secondseal bead is formed between the fluted sheet of the first layer offilter media and the second face of the facer sheet of the adjacentsecond layer of filter media closing off flutes formed between theadjacent first and second layers of fluted filter media. The first andsecond seal beads are axially spaced apart from one another along theflutes.

In a particular embodiment, each layer of fluted filter media includes asecond stitch bead formed between the fluted sheet and the first face ofthe facer sheet. The second stitch bead does not close the flutes formedbetween the fluted sheet and the first face of the facer sheet.

In an embodiment, the first stitch bead is a continuous bead of adhesiveextending entirely between adjacent peaks of the fluted sheet.

In an embodiment, the plurality of layers of fluted filter media areformed by winding a continuous piece of fluted filter media to formadjacent layers of fluted filter media.

In an embodiment, the plurality of layers of fluted filter media areformed from a plurality of strips of fluted filter media stacked on topof one another.

In one embodiment, a method of forming a filter media pack is provided.The method includes: securing adjacent layers of fluted filter media,each layer of fluted filter media including a fluted sheet forming aplurality of peaks and valleys attached to a first face of a facer sheetforming a plurality of flutes between the facer sheet and the flutedsheet extending between a first edge and a second edge, the facer sheetforming a second face opposite the first face; and wherein attachingadjacent layers includes providing at least one first stitch beadsecuring adjacent layers together, the first stitch bead being formedbetween the fluted sheet of a first layer of filter media and the secondface of the facer sheet of an adjacent second layer of filter media, thefirst stitch bead not closing the flutes formed between the first andsecond layer of filter media.

In an embodiment, the step of securing adjacent layers includes windinga continuous piece of fluted filter media to form adjacent layers.

In an embodiment, the step of providing the at least one first stitchbead occurs while winding the fluted filter media.

In an embodiment, the step of securing adjacent layers includes formingindividual strips of fluted filter media and stacking them to formadjacent layers.

In an embodiment, the method includes forming the fluted filter mediawhich includes securing the fluted sheet to the facer sheet with asecond stitch bead. The second stitch bead does not close off the flutesformed between the first face and the fluted sheet.

In an embodiment, forming the fluted filter media includes forming afirst seal bead while forming the fluted filter media. The first sealbead is formed between the fluted sheet and the facer sheet and closingoff the flutes formed therebetween. The method further includes forminga second seal bead between the adjacent layers. The second seal beadcloses off flutes between the fluted sheet of the first layer and thesecond face of the facer sheet of an adjacent second layer of filtermedia.

In an embodiment, the first and second seal beads each have an averagethickness that are thicker than an average thickness of the first stitchbead.

In an embodiment, the step of providing at least one stitch beadincludes applying the stitch bead directly to the peaks of the flutedsheet of the first layer and then pressing the second face of the facersheet of the adjacent second layer against the adhesive and peaks of thefirst layer.

In an embodiment, the step of providing at least one stitch beadincludes applying the stitch bead directly to the second face of thefacer sheet of the adjacent layer of fluted filter media and thenpressing the peaks of the fluted sheet of the first layer of flutedfilter media against the adhesive and second face of the facer sheet ofadjacent layer of fluted filter media.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings incorporated in and forming a part of thespecification illustrate several aspects of the present invention and,together with the description, serve to explain the principles of theinvention. In the drawings:

FIG. 1 is a perspective illustration of a filter element according to anembodiment of the invention;

FIG. 2 is a partial cross-sectional illustration of the filter elementof FIG. 1;

FIG. 3 is a perspective illustration of a layer of filter media formedfrom a corrugated sheet attached to a facer sheet;

FIG. 4 is an enlarged illustration of the seal arrangement of the filterelement of FIG. 2;

FIG. 5 is a further embodiment of a seal arrangement;

FIG. 6 is a simplified cross-sectional illustration of a filter elementhaving a reinforcing structure according to an embodiment of theinvention taken about line 6-6 of FIG. 1;

FIG. 7 is a partial cross-sectional illustration of the filter media ofFIG. 6 taken about line 7-7;

FIG. 8 is a simplified illustration of the step of applying areinforcing agent using a bath style application;

FIG. 9 is a simplified illustration of the step of hardening thereinforcing agent after it has been applied to a filter element;

FIG. 10 is a simplified perspective illustration of a method of applyingthe reinforcing agent while winding the filter media;

FIG. 11 is a further simplified embodiment of a filter element whereinthe reinforcing agent does not cover an entire cross-section of thefilter media and includes multiple reinforcing structures;

FIG. 12 is a simplified illustration of a further filter element havingpleated media utilizing features of the present invention;

FIG. 13 is a partial cross-sectional illustration of the embodiment ofFIG. 12;

FIGS. 14 and 15 are enlarged illustrations of embodiments of the tip ofthe pleats of the pleated media of FIG. 13 including reinforcing agentapplied thereto;

FIG. 16 illustrates a method of applying a stitch bead while winding afluted filter media pack;

FIG. 17 is a cross-sectional simplified illustration of the stitch beadformed using the process illustrated in FIG. 16;

FIG. 18 illustrates a method of applying a stitch bead while winding afluted filter media pack; and

FIG. 19 is a cross-sectional simplified illustration of the stitch beadformed using the process illustrated in FIG. 19.

While the invention will be described in connection with certainpreferred embodiments, there is no intent to limit it to thoseembodiments. On the contrary, the intent is to cover all alternatives,modifications and equivalents as included within the spirit and scope ofthe invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1-3 show a first embodiment of the present invention in the formof a filter element 100 adapted for insertion into a filter housing forremoving particulate matter from a flow of fluid passing through thefilter housing. The term fluid as used herein is intended to includefluids in either liquid or gaseous forms; however, the embodiments shownherein illustrate an air filter of the type used for filtering intakeair for engines and air compressors. It is understood that inventivefeatures may also be applicable to liquid applications.

The filter element 100 of the first embodiment is generally shown inFIGS. 1-2 as an annular shape with a race-track-like cross section. Theterm “annular” is used herein in accordance with the common dictionarydefinition to describe a variety of ring-like shapes disposed about anaxis or centerline. Annular shapes, as contemplated by the inventors,may include, but are not limited to, shapes that are round, rectangular,oval, or race-track-like with two generally straight and parallel sidesjoined by rounded ends.

To generally introduce different components, the filter element 100, asshown in FIGS. 1-2, includes a filter media pack 102 and a sealarrangement 104 for sealing with a housing in which the filter element100 is to be mounted.

The filter media pack 102 of the illustrated embodiment has opposed flowfaces in the form of an inlet face 110 and an outlet face 112.

In the illustrated embodiment, with additional reference to FIG. 3, thefilter media pack 102 is a fluted media pack formed from a plurality ofadjacent layers of filter media, which may include a flat sheet layerand a fluted or corrugated layer. The fluted filter media forms aplurality of inlet flutes 114 that have an open inlet end 116 adjacentthe inlet face 110 and a closed outlet end 118 adjacent the outlet face112. The closed outlet end 118 is closed by a sealing bead 120. Thefluted filter media also forms a plurality of outlet flutes 122 thathave a closed inlet end 124 that is closed by a sealing bead 126adjacent the inlet face 110. The outlet flutes 122 have an open outletend 128 adjacent the outlet face 112. Fluid to be filtered enters thefilter media pack 102 through the open inlet ends 116 of the inletflutes 114 passes through the porous filter media to the outlet flutes122 and out the open outlet ends 128 of the outlet flutes 122 throughthe outlet face 112.

With reference to FIG. 3, the fluted filter media includes a facer sheet130 of porous filter media and a fluted sheet 132 (also referred to as acorrugated sheet) of porous filter media secured together to form alayer of fluted filter media. Typically, the facer sheet 130 is attachedto the fluted sheet 132 by a first bead of sealant that also forms oneof the inlet or outlet sealing beads 120, 126 that closes one of theends of either the inlet or outlet flutes 114, 122.

The fluted sheet 132 may be formed by any appropriate process, such ascorrugating or pleating, but preferably by gathering as described inU.S. Patent Publication No. 2006/0091066, entitled “Gathered FilterMedia for an Air Filter and Method of Making Same,” assigned to theAssignee of the present invention, and incorporated herein by reference.The term “facer sheet”, as used herein, is intended to encompass anyform of sheet or strip of generally flat, porous or non-porous, materialattached to the fluted sheet of porous filter material. In mostembodiments of the invention, the facer sheet would preferably be formedof a porous filter material. Further, the facer sheet would typically beflat, but could be corrugated or otherwise shaped as well.

The fluted filter media for the filter element 100 of FIGS. 1-2 is woundaround a winding core 134 to provide the plurality of adjacent layers.As the fluted filter media is wound, a second bead of sealant is appliedbetween the facer sheet of one layer and the fluted sheet of theadjacent layer. This second bead of sealant is axially offset from thefirst bead of sealant along the flutes and is typically locatedproximate the opposite end of the flutes. This second bead of sealantwill form the other one of the outlet or inlet sealing beads 126, 120that closes the other end of the outlet or inlet flutes 122, 114.

The winding core 118 can take various shapes and dimensions. One exampleof the winding core 118 is disclosed in U.S. patent application Ser. No.11/634,647, entitled “Fluid Filter Apparatus Having Filter Media WoundAbout a Winding Frame,” assigned to the Assignee of the presentinvention, and incorporated herein by reference. In alternativeembodiments, the fluted filter media pack 102 may be formed withoutusing a winding core.

In the illustrated embodiment, the seal arrangement 104 is providedproximate the inlet face 110 of the filter media pack 102. The sealarrangement 104 includes a seal member 140 for engaging a housing havinga sealing surface (not shown). In the illustrated embodiment, the sealmember 140 provides an axial seal. However, in other embodiments, theseal member 140 could be configured to provide a radial seal.

The seal member 140 has a sealing surface 142 configured to seal againstthe sealing surface of the filter housing to form an axial seal betweenthe filter housing and the filter element 100. When the filter element100 is placed in the filter housing, the seal member 140 is compressedagainst the sealing surface of the filter housing such that the sealingsurface 142 of the seal member 140 and the sealing surface of the filterhousing provide a seal between the filter element 100 and the housing toprevent any unfiltered air from bypassing the filter media pack 102while flowing through the filter housing. The seal member 140 may beformed of any suitable sealing materials including but not limited topolymeric materials and polymer foams, preferably, urethane foam.Expandable materials such as urethane are particularly advantageousbecause they are resilient to provide a sealing function and can bemolded directly to the filter media pack 102 or onto a seal supportmember 144, such as illustrated in FIGS. 1-2. Further yet, the sealmember 140 could be separately formed and then adhesively or otherwisesecured to the filter media pack 102 or the seal support member 144.

When mounted in an air supply system, such as an air intake system foran engine, these filters are typically exposed to a suction applied atthe outlet face 112 as illustrated by suction force S in FIG. 1. Thissuction force S tends to cause the filter media and layers of filtermedia to compress radially inwardly as illustrated by arrows 146.

This inward compression can pose several problems. First, this can causethe layers of filter media to separate and create possible leak paths.Further, this can cause the filter media to separate from the sealarrangement 104 depending on the rigidity of the seal arrangement 104 orhow tightly the seal arrangement 104 is axially engaged with the housingin an axial sealing configuration. Further, if the seal arrangement 104provides a radial seal with the housing, the inward compression of thefilter media pack 102 can likewise draw the seal arrangement radiallyinward reducing the seal engagement between the seal arrangement 104 andthe sealing surfaces of the filter housing. This is particularly true ifthe seal arrangement 104 is merely the seal member 140 secured to thefilter media pack 102 without any more rigid support member.

A further problem associated with the pressure differential across thefilter element 100 and flow of air through the filter element 100 isthat the layers of filter media can telescope axially. Moreparticularly, adjacent layers of the filter media will slip axiallyrelative to one another which can create leak paths as well asexacerbate the issues relating to radial compression discussedpreviously.

With reference to schematic illustrations of FIGS. 6 and 7, embodimentsof the invention incorporate a reinforcing structure 150 to reinforcethe layers of fluted media to prevent one or more of the problemsidentified above.

The reinforcing structure 150 in FIG. 6 is located adjacent the inletface 110. However, it could be located adjacent the outlet face 112 ormultiple structures could be provided, such as one adjacent the inletface 110 and one adjacent the outlet face 112. Further, a reinforcingstructure could be axially offset from the inlet and outlet faces 110,112 and be positioned axially inward therefrom.

The reinforcing structure is a composite structure formed from areinforcing component formed from a reinforcing agent 152 and the sheetsof filter media including the face and fluted sheets 130, 132.Preferably, the reinforcing agent is impregnated into the face andfluted sheets 130, 132. In FIGS. 6 and 7, the reinforcing agent 152 isshown as an outer layer of material around the filter media of sheets130, 132 with an exaggerated thickness for ease of illustration.

Typically, the reinforcing agent 152 will be applied as a liquid andthen operably hardened, and more preferably hardened to a solid toprovide reinforcement of the media pack 102. In the liquid form, thereinforcing agent 152 will be absorbed into and preferably entirelythrough the pores of portions of the various sheets of media 130, 132 tofurther reinforce the media pack 102. This is illustrated by thecross-hatching of the reinforcing agent 152 extending into the crosshatching of the sheets 130, 132 and entirely therethrough such as atregions 154 and 156 in FIG. 7. Typically, at regions 156 there is noadhesive between the facer sheet 130 and the fluted sheet 132 proximatethis end of the media pack 102. As such, by using the reinforcing agent152 an adhesive bond between these two sheets 130, 132 is now providedto further support and strengthen the media pack 102.

After application, the reinforcing agent 152 will harden to form amatrix that penetrates the pores of the media and encapsulates thematerial of the media, such as fibers thereof. The media thus provides asubstrate of the composite structure. This hardened reinforcingstructure 150 provides additional bonding between the various sheets toincrease the rigidity of the media pack 102. The reinforcing structure150 will provide additional axial reinforcement to prevent telescopingor slipping of adjacent layers, such as along axis 160 that is typicallynot present in fluted media, i.e. such as at location 156. Thereinforcing structure 150 will also provide further rigidity to provideradial support and strength to prevent or inhibit radial compression orexpansion of the media pack 102 toward or away from axis 160 dependingon whether the media pack 102 is exposed to a positive or negativedifferential pressure.

The reinforcing agent 152 will typically be applied to the filter mediapack in a flowable state. Typically, the reinforcing agent 152 will be aliquid having a low viscosity. Preferably, the viscosity will be below1000 centipoise. More preferably, the viscosity is less than 800centipoise. Even more preferably, the viscosity is between 350 and 650centipoise and even more preferably between 400 and 600 centipoise.However, it is contemplated that viscosities less than 350 centipoisewould provide very positive wicking characteristics. Other embodimentscould use a powder material that is applied to the media pack 102. Thepowder material could then be converted to a rigid structure by asecondary process such as heating or applying a curing or hardeningagent.

Typically, the viscosity of the reinforcing agent 152 will besubstantially less than the viscosity of the sealant for the first andsecond beads 120, 126. This is because it is desired that thereinforcing agent does not plug or restrict flow of fluid through theflutes. The sealant for the first and second beads 120, 126 may beformed from numerous different materials but is often formed from a hotmelt. When dispensed, the sealant for the first and second beads 120,126 will often be above 5,000 centipoise, and in some instances muchmore viscous such as above 10,000 centipoise. The sealant for beads 120,126 will become more viscous as the sealant cures and hardens afterbeing applied to the media as the sealant cools, particularly when a hotmelt type product is used. The higher viscosity of the sealant beads120, 126 is used such that the sealant beads 120, 126 are sufficient toseal off and close desired ones of the flutes, as illustrated in FIGS. 2and 7.

With reference to FIG. 8, in one embodiment, the media pack 102 is firstformed from the filter media. This could be done by winding a continuouslayer of media formed from a facer sheet and a fluted sheet to form aplurality of adjacent layers or stacking a plurality of segments oflayers to form the media pack 102.

The media pack 102 is then dipped into a bath 162 of liquid or otherwiseflowable reinforcing agent 152, such as illustrated by arrow 164 alongaxis 160 and perpendicular to the inlet and outlet faces 110, 112. Thedipping may be to a dipping depth d1 (also referred to as an emersiondepth) that is equal to or less than the ultimate depth d2 (see FIG. 6)of the reinforcing agent 152 from the corresponding flow face 110, 112of the media pack 102. The ultimate depth d2 may also be referred to asthe reinforced distance. Typically, the dipping depth d1 will be lessthan the ultimate depth d2 as the reinforcing agent 152 will wickaxially into the media pack 102 further than the dipping depth d1. Forinstance, with some products that have been tested, the dipping depth d1was approximately ⅓ the of the ultimate depth d2 of the reinforcingagent 152.

During this dipping process, the flowable reinforcing agent 152 willpreferably penetrate into and through the pores within the media toincrease the strength of the ultimate reinforcing structure 150 whencompleted. However, in other embodiments, the reinforcing agent 152could merely coat the outer surfaces of the media.

The media pack 102 will then be axially lifted out of the bath 160,illustrated by arrow 168.

After the media pack 102 is removed from the bath 162, the liquidreinforcing agent 152 applied to the filter media will be hardened.Prior to hardening, in some embodiments, forced air is blown through thefilter element to help clear excess reinforcing agent 152 from the openended flutes.

FIG. 9 illustrates the reinforcing agent 152 being hardened by ahardening mechanism 166.

Depending on the type of reinforcing agent 152, the hardening mechanism166 may vary. For instance, in some embodiments, the reinforcing agent152 may be ultraviolet curable. As such, the hardening mechanism 166could be an ultraviolet light. The reinforcing agent 152 could also beconfigured to cure based on a different wavelength of light as well,such as a wavelength within the visible light spectrum. Alternatively,the hardening device 166 could be a fan for blowing air against theliquid reinforcing agent. Further, the hardening device could be aheater or even an oven for heat hardening the reinforcing agent. Furtheryet, in other embodiments, the reinforcing agent 152 could be in theform of a multi-part material such as a multi-part epoxy where thehardening device 166 applies a second component to cause a firstcomponent, i.e. the component that would be in bath 162, to cure andharden.

The seal arrangement 104 can then be attached to the media pack 102.Preferably, the seal member 104 is mounted to the media pack 102proximate the axial location along axis 160 of the reinforcing structure150. In at least some embodiments, such as illustrated in FIG. 6, theseal arrangement 104 will at least partially axially overlap with thereinforcing structure 150.

The ultimate depth d2 of the reinforcing structure 150 is preferablybetween ¼ and ½ inch. However, other depths d2 are permissible dependingon the overall length L of the media pack 102, the width W of the mediapack 102 and the ultimate pressure drop across the media pack 102 (seee.g. FIG. 6). For instance, in some embodiments, ultimate depth d2 maybe as low as 0.100 inch.

With reference to FIG. 10, in another embodiment, a method of formingthe reinforcing structure 150 applies the reinforcing agent 152 whileforming the media pack 102. More particularly, the reinforcing structure150 is applied either during winding or stacking of the layers of mediato form the plurality of layers.

In this embodiment, one of the sealant beads, e.g. sealant bead 126 (notshown in FIG. 10), is already applied between a facer sheet 130 and afluted sheet 132 to form a layer of fluted filter media proximate inletend 110. The layer of fluted filter media is being wound around windingcore 134.

During the winding process, the second sealant bead 120 is being appliedto secure adjacent layers of filter media together. Simultaneously, thereinforcing agent 152 is being applied to the filter media in a flowablestate. In this embodiment, a first reinforcing agent applicator 170applies reinforcing agent 152 to the exposed surface of the fluted sheet132. A second reinforcing agent applicator 172 applies the reinforcingagent 152 to the exposed surface of the facer sheet 130 in line with thefirst reinforcing agent applicator 170. As the filter media is wound,the two separately deposited portions of reinforcing agent 152 willalign. By applying the reinforcing agent 152 to both sheets 130, 132, itis contemplated that better penetration into both sheets 130, 132 ofmedia may be achieved rather than relying on transfer from one sheet tothe other if only a single applicator was provided. However, the use ofa single applicator is not excluded from embodiments.

In this embodiment, the reinforcing agent 152 is applied proximate inletface 110. However, the reinforcing agent 152 could be applied proximatethe outlet face 112. Additionally, multiple reinforcing structures couldbe provided such that the reinforcing agent 152 could be applied atmultiple separate locations, such as proximate both the inlet and outletfaces 110, 112. Even further, a reinforcing structure could be locatedat an axial location between the inlet and outlet faces 110, 112, forexample, proximate a midpoint between the inlet and outlet faces 110,112.

In FIG. 10, a sealant applicator 178 applies sealant bead 120 proximateoutlet end 112 simultaneously as the reinforcing agent applicators 170,172 apply reinforcing agent 152 to the media. Sealant applicator 178 mayalso apply an initial sealant bead that seals the media to the windingcore 134. This initial sealant bead may include a portion that runslongitudinally parallel to the flutes and winding core 134, i.e. in adirection extending between the inlet and outlet faces 110, 112.

In some embodiments, the sealant beads 120, 126 (see also FIGS. 2 and 6)are formed from a material having different physical properties than thereinforcing agent 152. Typically, the material of the sealant beads 120,126 has a much higher viscosity value than the reinforcing agent 152, intheir respective flowable states. This is because the sealant materialfor sealant bead 120, 126 is configured to plug the channels formedbetween the facer sheet 130 and fluted sheet 132 to force the air topass through the porous filter media.

However, the reinforcing agent 152 is selected to specifically preventor inhibit plugging the open channels formed between the facer sheet 130and fluted sheet 132 and to be substantially completely absorbed intothe media or to more closely conform to the shape of the media in arather uniform thickness. The low viscosity of the reinforcing agentallows it to closely conform to the surfaces of the media. As such,excess reinforcing agent will drip from the filter media when using thebath style application or will closely conform to the shape of thesheets of media (e.g. facer sheet 130 and fluted sheet 132) when usingother types of applicators such as a spray application, wipingapplication, etc. Due to the low viscosity relative to the sealantmaterial, a globule of the reinforcing agent 152 should not remainwithin one of the grooves of the valleys or grooves of the fluted mediasuch that the flute formed by that groove would be plugged, unlike forsealant beads 120, 126. In some embodiments, where a more viscousmaterial is used, as noted above, air may be blown through the mediapack prior to hardening of the reinforcing agent 152 to help blow excessmaterial out of the open ends of the flutes to prevent undesiredplugging.

Ideally, only a very small outer layer of the reinforcing agent 152extends outward from the surfaces of the filter media such that only aminimum amount of the flute openings would be closed or otherwiseblocked due to the reinforcing agent 152 when it hardens. In someembodiments, the reinforcing agent 152 blocks less than 20% of thecross-sectional area of an open flute and even more preferably less than10%. Again, the drawings have the thickness of the reinforcing agent 152exaggerated for illustrative purposes.

When the reinforcing agent 152 is applied while forming the media pack102, the seal arrangement 104 will be attached to the media pack afterthe step of applying the reinforcing agent. Typically, the sealarrangement 104 would be attached after the sealing agent 152 has been,at least partially, hardened. However, this order is not required.

While the prior embodiments disclose a reinforcing structure 150 thatwould be applied to substantially the entire cross-sectional area(perpendicular to the longitudinal axis 60, e.g. flow axis) of thefilter media of the media pack 102, other embodiments could apply thereinforcing agent 152 to only a portion of the media pack. For example,if the media pack is a wound media pack having twenty (20) wound layers,the reinforcing agent 152 may only be applied to the first ten (10)inner layers or the outer ten (10) layers but not to all twenty (20)layers.

If the reinforcing agent 152 is applied as illustrated in FIG. 10 duringthe winding process, the application of the reinforcing agent 152 couldbe started or stopped to apply the reinforcing agent 152 at the desiredlocation of the cross-section. Further, multiple locations of thecross-section could have reinforcing agent 152. This is illustrated inFIG. 11 by regions 180, 182. In this embodiment, only the portion of theinlet end face 110 in regions 180, 182 has a reinforcing structurepresent. While this embodiment shows an inner reinforcing structure(region 180) and an outer reinforcing structure (region 182), otherembodiments could have more or less regions than that are illustrated.Further, while the regions are illustrated at the inlet face 110, thedifferent regions could be at the outlet face 112 or at an axiallocation between the inlet and outlet faces 110, 112.

Individual regions would typically apply the reinforcing agent tomultiple adjacent layers of media. The reinforcing agent could beapplied to as little as one specific layer; however, it would typicallybe applied to at least two adjacent layers of the media.

If the reinforcing agent 152 is applied after the media pack 102 isformed, the applicator for applying the reinforcing agent 152 could be asprayer or brush or a sponge like applicator that applies thereinforcing agent 152 to the desired regions of the cross-section of themedia pack 102. The brush or sponge could perform a wiping typeapplication. Such a wiping type application could also be used duringthe application such as in FIG. 10, rather than spraying.

With reference to FIG. 6, it is contemplated to be beneficial to offsetthe sealant bead, e.g. sealant bead 126, from the inlet face 110 oroutlet face 112 if the reinforcing structure 150 is going to be adjacentthereto. With reference to the inlet face 110, but with equalapplicability to the outlet face 112, this allows the portion of thefilter media 190 between the inlet face 110 and the sealant bead 126 toabsorb the reinforcing agent 152 and form a strong adhesion between theplurality of layers of filter media without interference from thesealant bead 126. However, this is not necessary.

The Applicants have tested the concept of including such a reinforcingstructure and have had very successful results relating to structuralintegrity (e.g. telescoping or failure).

Additionally, similar media packs were tested to determine the effect onoverall pack efficiency and capacity. A standard pack (no reinforcementstructure) and two media packs including the reinforcement structure 150at the outlet face were tested using an ISO 5011 test where at a flowrate of 565 SCFM using an airborne contaminant of PTI Fine 11968F, wasused until a differential pressure of 30 inch H₂O was reached. One ofthe media packs (referred to herein as Test Element A) including thereinforcement structure had a minimum amount of reinforcing agent suchthat it had an ultimate depth of less than ⅛ inch from the outlet face.Another one of the media packs (referred to herein as Test Element B)including the reinforcement structure had a larger amount of reinforcingagent such that it had an ultimate depth of on average between ⅛ inchand ¼ inch of reinforcing agent extending towards the inlet face.

From this test, the pack with the larger amount of reinforcing agentactually had better accumulated efficiency, larger capacity and a loweramount by weight of bypassed particulate. These results were generallyexpected as the reinforcing structure was positioned proximate thedownstream outlet face adjacent the corresponding sealant bead wherelittle to no fluid filtration occurs due to the sealant beads inhibitingfluid flow through that portion of the filter media.

The following specific test results were captured:

Standard Pack Test Element A Test Element B Test Time (min) 23.9 23.324.0 Initial Restriction 3.6 3.6 3.6 (inches of H₂O) Acc. Efficiency99.97 99.98 99.99 Capacity (Grams) 756.69 737.15 758.50 Grams Bypassed0.21 0.15 0.10

FIG. 12 is further embodiment of a filter element 300 according to thepresent invention. This filter element 300 included a pleated media pack302 mounted within a frame structure 303. The frame structure mayinclude a seal arrangement for sealing the media pack within filterhousing to prevent fluid bypass. The filter media pack 302 will besealed within the frame structure 303 with a sealant 313 to preventfluid bypass between the media pack 302 and the frame structure 303. Theframe structure can take many forms and could be provided by urethane(particularly foamed urethane), plastic frame materials, a combinationof the urethane and plastic materials. When a urethane is used, it maytake the form of both the frame structure 303 and the sealant 313. Thesealant 313 also seals the open ends of the pleats.

With additional reference to FIG. 13, the filter element 300 is shown inpartial cross-section. As can be seen in FIG. 13, the pleated media pack302 is generally a single sheet of media that is folded to form aplurality of adjacent panels 306 that form a plurality of peaks 307 andvalleys 308. The peaks 307A form an inlet side or inlet face of thefilter element 300 while the peaks 307B form an outlet side or outletface of the filter element 300. The valleys that open toward the inletface are referred to as inlet valleys 308A and the valleys that opentoward the outlet face are referred to as outlet valleys 308B.

The peaks 307 are generally the folds that connect adjacent panels 306of the media.

The peaks 307 of the filter element 300 are impregnated with areinforcing agent 352 to provide strength to the media pack 302. Thisarrangement may be referred to as a peak reinforcing structure. Thereinforcing agent 352 is illustrated as heavy thick lines while filtermedia without the reinforcing agent 352 is shown schematically as thinlines.

Again, like with previous embodiments using fluted media, it ispreferred that the reinforcing agent 352 extends into the pores of thefilter media and through the filter media. However, it is possible thatit could be provide more as a coating in some embodiments.

In some embodiments, such as illustrated in FIG. 13, the reinforcingagent could extend between peaks 307A and 307B along a face of thepanels as illustrated by reinforcing agent 353 to provide additionalrigidity and structural support to the pleats. This rigidity can helpkeep adjacent panels 306 of filter media from collapsing on one anotherand closing the valleys 308A, 308B such that the filtering capacity ofthe filter element 300 is diminished. While only a single strip ofreinforcing agent 353 is illustrated, multiple strips could be providedbetween opposed edges of the filter media. Multiple strips areillustrated in FIG. 12. Again, preferably, the reinforcing agent 353penetrates through the filter media to form a composite reinforcingstructure formed from the reinforcing agent 353 and the material of thefilter media. It is noted that the portion of reinforcing agent 352 onthe peaks 307A, 307B can also provide rigidity and help keep the peaks307A, 307B separated.

Preferably, the width w2 of the strips of reinforcing agent 353, alsoreferred to as intermediate reinforcing structures, is between about ⅛inch and ⅜ inch so as to provide sufficient strength or support withoutunduly limiting the filter capacity of the filter media.

Similarly, the depth d3 that the reinforcing agent 352 penetrates from agiven peak 307A, 307B towards the next peak 307B, 307A (i.e. from theinlet face towards the outlet face or from the outlet face towards theinlet face along a given panel) is preferably between about ⅛ inch and ¼inch so as to provide protection and strength to the corresponding peaks307A, 307B. FIG. 14 is an enlarged cross-sectional illustration of onepeak 307A illustrating reinforcing agent 352 applied to the peak 307A.Preferably, the reinforcing agent 352 extends entirely through thefilter media. It should be noted that, like before, the thickness of thereinforcing agent 352 is exaggerated for illustrative purposes only.

In some embodiments, the reinforcing agent 352 will not fully fill theportion 311 of the corresponding valley 308B proximate the peak 307A andwill generally form a V-shape. In alternative embodiments, thereinforcing agent could entirely fill the portion 311 (see e.g. FIG. 15)to be similar to a triangular shape of reinforcing agent 352.

The application of the reinforcing agent 352 to the peaks 307 helpsprevent cracking or damage to the peaks 307 due to impingement of fluidflow and impurities as well as the cyclical pressure loading that can beapplied to the filter media during a duty cycle of a filter element.

The reinforcing agent 352, 353 could be applied similar to those methodsabove such as dipping in a bath, spraying, or brushing/wiping.

Typically, the sealant 313 will have a different characteristic than thereinforcing agent 352, 353 but need not be in all embodiments.Typically, the reinforcing agent 352, 353 will have a lower viscositythan the sealant 313.

When pleated filter media is used, it is desired that the reinforcingagent covers less than 20% of the surface are of the filter media, morepreferably, less than 10% of the surface area of the filter media andeven more preferably less than 5% of the surface area of the filtermedia.

FIG. 16 illustrates a further embodiment of a method of forming a filtermedia pack. In this embodiment, the resulting filter element is againformed by winding filter media to form a plurality of layers of filtermedia. In this embodiment, during the winding process as well asapplication of bead 120, a plurality of reinforcing stitch beads 452 arebeing applied by applicators 472. The stitch beads help secure theadjacent layers of the filter media together and prevent telescoping aswell as improved rigidity for the resulting filter media pack.

The stitch beads 452 are applied between the adjacent layers of media.The stitch beads 452 are thin layers of adhesive used to secure theexposed peaks 407 of the fluted sheet 432 to the exposed surface 435 ofthe facer sheet 430. While a high penetration adhesive may be used otherhigher viscous adhesive such as a hot melt may also be used.

The thickness of the stitch beads 452 is such that the open flutes, i.e.regions formed between peaks 407 of the fluted sheet, are not blocked bythe adhesive forming the stitch beads 452.

In this embodiment, each of the stitch beads 452 is a continuous stripof adhesive applied to surface 435 during the winding process. In otherembodiments, the stitch bead 452 could be intermittently applied.

FIG. 17 is a simplified cross-sectional illustration of adjacent layersof filter media after formation using the process illustrated in FIG.16. Here, adhesive stitch beads 452 were applied to surface 435 of facersheet 430. In this illustration, the adhesive forming stitch beads 452only slightly penetrates into the fluted sheet 432 (e.g. at the peaks407) and surface 435 of the facer sheet 430. As illustrated, theadhesive only slightly interferes with the open flutes 444 formedbetween adjacent peaks 407 and surface 435 of the facer sheet 430.Preferably, the stitch beads 452 fill less than 10% of thecross-sectional area of the open flutes 444 and preferably less than 5%of the cross-sectional area of the open flutes 444.

While the embodiment of FIG. 16 illustrates a plurality of stitch beads,some embodiments may have only a single stitch bead while otherembodiments may have more than two stitch beads.

While being applied during the winding process, other embodiments couldincorporate such a stitch between adjacent stacked layers of filtermedia. Further, while FIG. 16 only illustrates a stitch bead beingformed while winding the layers of fluted filter media, stitch beadscould also be formed to hold the fluted sheet 432 to the facer sheet 430during the initial formation of the layer of filter media.

Preferably, the adhesive used to form the stitch bead has a quick curerate (also referred to as quick setting). This type of adhesive is oftenreferred to as having an aggressive green-tack. In one embodiment, thestitch bead could be formed by a visible light cure adhesive where theadhesive is cured proximate the time at which the two layers of mediaare being brought together.

While the stitch beads 452 help the structural integrity of theresulting media pack, the stitch beads 452 also help resist synching ofthe layers of filter media during the winding process, e.g. to inhibitslipping of adjacent layers during winding in a direction perpendicularto axis around which the layers of filter media are wound.

As illustrated in FIG. 17, because the stitch bead is not a seal bead,the stitch bead 452 will have less adhesive at a given location than thecorresponding seal bead. For instance, the thickness of a stitch beadwhen measured perpendicular to the layer of media will be less than thethickness of a seal bead as it is being applied during manufacture.

In this embodiment, seal bead 420 is being applied during the windingprocess to close off one end of the flutes that are formed between theadjacent layers of fluted filter media. The other seal bead would beformed during the process of forming the fluted filter media and wouldbe located between the facer sheet 430 and the fluted sheet 432. Thesetwo seal beads are axially spaced apart and located proximate oppositeedges of the layer of fluted filter media. Further, the stitch beads 452are illustrated as being axially spaced from seal bead 420 along theaxis of the flutes.

FIGS. 18 and 19 illustrate a further embodiment that is similar to thosedescribed with reference to FIGS. 16 and 17. Here, a stitch bead 552 isagain being applied between adjacent layers of wound filter media.Rather than applying a bead of adhesive to surface 535 of the facersheet 530, the adhesive for the stitch bead 552 is applied directly tothe peaks 507 with applicator 570. The applicator 570 may be apressurized ejector or could operate in other manners such as by arolling action or a wiping action to apply the adhesive to peaks 507.

As the filter media is being wound, the adhesive forming stitch bead 552is sandwiched between the exposed peaks 507 of the fluted sheet 532 andsurface 535 of facer sheet 530.

In this embodiment, each stitch bead is applied as an intermittent beadof adhesive. One benefit of this arrangement is that very limited wastedadhesive is applied between the layers of the filter media. Moreparticularly, adhesive is not unnecessarily applied to surface 535 ofthe facer sheet 530 between the peaks where the adhesive does notcontact any portion of the fluted sheet 532. This limits wasted materialas well as prevents unnecessary blocking of the filter media of thefacer sheet 530 between the peaks.

As illustrated, the adhesive only slightly interferes with the openflutes 544 formed between adjacent peaks 507 and surface 535 of thefacer sheet 530 and to a lesser extent than the prior embodiment.Preferably, the stitch beads 552 fill less than 10% of thecross-sectional area of the open flutes 544 and preferably less than 5%of the cross-sectional area of the open flutes 544. Again, the stitchbeads 552 do not block the open flutes formed between the adjacentpeaks. The blocking of the open flutes occurs by the application of sealbead 520.

Again, stitch beads can be applied to both sides of the fluted sheet530. More particularly, stitch beads may be applied between the facersheet 530 and the fluted sheet 532 during the formation of the layer offluted filter media. The stitch bead would assist in maintaining thepeaks and valleys of the fluted sheet 532 during the formation process.Again, these stitch beads would not block the open flutes formed betweenadjacent peaks.

All references, including publications, patent applications, and patentscited herein are hereby incorporated by reference to the same extent asif each reference were individually and specifically indicated to beincorporated by reference and were set forth in its entirety herein.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) is to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

1. A filter media pack comprising: filter media having an inlet face andan outlet face; a reinforcing structure being a composite structurecomprising a reinforcing agent impregnated into the filter media suchthat the filter media forms a substrate and the reinforcing agent formsa hardened matrix.
 2. The filter media pack of claim 1, wherein thefilter media forms a plurality of pores therethrough and the reinforcingagent extends through at least some of the pores entirely through thefilter media.
 3. The filter media pack of claim 1, wherein thereinforcing structure is formed proximate one of the inlet face andoutlet face.
 4. The filter media pack of claim 1, further comprising aseal arrangement attached to the filter media proximate the reinforcingstructure. 5-6. (canceled)
 7. The filter media pack of claim 1, whereinthe filter media is z-media having a plurality of adjacent layers offluted filter media defining the inlet face and the outlet face, eachlayer including a corrugated sheet and a facer sheet attached to thecorrugated sheet, the layers of fluted filter media, forming a pluralityof inlet and outlet flutes extending between the inlet and outlet faces;wherein the inlet flutes are open proximate the inlet face and closedproximate the outlet face by outlet end sealant and the outlet flutesare closed proximate the inlet face by inlet end sealant and openproximate the outlet face, the reinforcing agent being different thanthe inlet end sealant and outlet end sealant.
 8. The filter media packof claim 1, wherein the filter media is z-media having a plurality ofadjacent layers of fluted filter media defining the inlet face and theoutlet face, each layer including a corrugated sheet and a facer sheetattached to the corrugated sheet, the layers of fluted filter mediaforming a plurality of inlet and outlet flutes extending between theinlet and outlet faces; and wherein the inlet flutes have an open endproximate the inlet face and a closed end proximate the outlet face andthe outlet flutes have a closed end proximate the inlet face and an openend proximate the outlet face, the reinforcing agent does not close theopen ends of the flutes.
 9. (canceled)
 10. The filter media pack ofclaim 1, wherein the filter media is pleated filter media forming aplurality of adjacent panels connected by folds forming a plurality ofpeaks and valleys.
 11. The filter media pack of claim 10, wherein thereinforcing agent is applied to at least one of the peaks of the filtermedia to provide at least part of the reinforcing structure. 12-19.(canceled)
 20. A method of providing reinforcing of a media packcomprising: forming a media pack to have an inlet face and an outletface; applying a reinforcing agent to the media pack, the reinforcingagent being applied in a flowable state; and hardening the reinforcingagent to form a reinforcing structure to reinforce the media pack. 21.The method of claim 20, wherein the reinforcing agent is appliedproximate to at least one of the inlet face and the outlet face
 22. Themethod of claim 20, wherein applying the reinforcing agent includesimmersing the at least one of the inlet face and the outlet face in thereinforcing agent in a bath of reinforcing agent in the flowable state.23. The method of claim 22, wherein applying the reinforcing agentincludes immersing less than the entire media pack in the reinforcingagent.
 24. The method of claim 20, wherein the reinforcing agent is aliquid.
 25. The method of claim 20, wherein the reinforcing agent is apowder.
 26. The method of claim 20, wherein the step of hardeningincludes exposing the reinforcing agent to a predetermined wavelength oflight.
 27. The method of claim 26, wherein the predetermined wavelengthof light is UV.
 28. The method of claim 20, wherein the step ofhardening includes heating the reinforcing agent.
 29. The method ofclaim 20, wherein the step of hardening includes actively drying thereinforcing agent.
 30. (canceled)
 31. The method of claim 20, whereinthe media pack is z-media having a plurality of adjacent layers offluted filter media defining an inlet face and an outlet face, eachlayer including a corrugated sheet and a facer sheet attached to thecorrugated sheet to form a plurality of inlet and outlet flutesextending between the inlet and outlet faces; and wherein the inletflutes have an open end proximate the inlet and a closed end proximatethe outlet face and the outlet flutes have a closed end proximate theinlet face and an open end proximate the outlet face, the reinforcingagent does not close the open ends of the flutes.
 32. The method ofclaim 20, wherein the media pack is z-media having a plurality ofadjacent layers of fluted filter media defining an inlet face and anoutlet face, each layer including a corrugated sheet and a facer sheetattached to the corrugated sheet to form a plurality of inlet and outletflutes extending between the inlet and outlet faces; and wherein theinlet flutes are open proximate the inlet and closed proximate theoutlet face by outlet end sealant and the outlet flutes are closedproximate the inlet face by inlet end sealant and open proximate theoutlet face, the reinforcing agent being different than the inlet endsealant and outlet end sealant.
 33. The method of claim 32, wherein theinlet and outlet end sealant have a higher viscosity than thereinforcing agent when applied.
 34. The method of claim 32, wherein thereinforcing agent overlaps, at least in part, at least one of the inletend sealant and the outlet end sealant.
 35. The method of claim 20,wherein the media pack is z-media having a plurality of adjacent layersof fluted filter media defining an inlet face and an outlet face, eachlayer including a corrugated sheet and a facer sheet attached to thecorrugated sheet to form a plurality of inlet and outlet flutesextending between the inlet and outlet faces; and wherein thereinforcing agent is applied such that the reinforcing agent attaches aportion of a corrugated sheet to an adjacent portion of an adjacentfacer sheet that was not otherwise attached.
 36. The method of claim 32,wherein the reinforcing agent is applied such that the reinforcing agentattaches a portion of a corrugated sheet to an adjacent portion of anadjacent facer sheet that was not otherwise attached by either the inletor outlet end sealant.
 37. The method of claim 36, wherein thereinforcing agent is axially located adjacent at least one of the inletand outlet end sealant.
 38. The method of claim 20, further comprisingattaching a seal member to the media pack adjacent the reinforcingagent; and wherein a portion of the seal member overlaps with a portionof the reinforcing agent. 39-44. (canceled)
 45. The method of claim 20,wherein the step of applying the reinforcing agent includes absorbingthe reinforcing agent into media of the media pack. 46-54. (canceled)55. The method of claim 20, wherein the reinforcing agent extends atleast 0.100 inch into the filter media pack from the corresponding face.56. The method of claim 20, wherein hardening the reinforcing agentincludes applying a second material to the reinforcing agent to cure thereinforcing agent.
 57. The method of claim 56, wherein the reinforcingagent and second material are a multipart epoxy.
 58. The method of claim20, wherein the reinforcing agent is impregnated into the media of thefilter media pack which forms a substrate, the reinforcing agent extendsthrough the media prior to the step of hardening such that thereinforcing structure is comprised of a matrix of the hardenedreinforcing agent and the media substrate. 59-84. (canceled)